Michael Alifrangis

Michael Alifrangis
University of Copenhagen · Centre for Medical Parasitology

About

187
Publications
26,479
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4,905
Citations
Citations since 2017
71 Research Items
2229 Citations
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20172018201920202021202220230100200300400

Publications

Publications (187)
Preprint
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Background Artemisinin-based combination therapies (ACTs) are the first-line treatments for uncomplicated malaria in Ghana. Artemisinin (ART) tolerance in Plasmodium falciparum has arisen in Southeast Asia (SEA) and recently, in parts of East Africa. This is ascribed to the survival of ring-stage parasites post treatment. We sought to assess and ch...
Article
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Background The prevalence of small for gestational age (SGA) may vary depending on the chosen weight-for-gestational-age reference chart. An individual participant data meta-analysis was conducted to assess the implications of using a local reference (STOPPAM) instead of a universal reference (Intergrowth-21) on the association between malaria in p...
Article
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The Mali National Malaria Control Program (NMCP) recently established a phased set of goals for eliminating malaria in Mali by 2030. Over the past decade, the scale-up of NMCP-led malaria control interventions has led to considerable progress, as evidenced by multiple malariometric indicators. The West Africa International Center of Excellence in M...
Article
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This article highlights over a decade of signature achievements by the West Africa International Centers for Excellence in Malaria Research (WA-ICEMR) and its partners toward guiding malaria prevention and control strategies. Since 2010, the WA-ICEMR has performed longitudinal studies to monitor and assess malaria control interventions with respect...
Chapter
Molecular studies related to diagnosis and research rely on collection of blood samples and extraction of high-quality DNA. In Africa, where the populations carried 94% of the total burden of cases and deaths due to malaria in 2019, collection of samples is often challenged by remote study areas and lack of a cold chain to transport and store sampl...
Article
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In Africa, children aged 5 to 15 years (school age) comprises more than 50% (>339 million) of the under 19 years population, and are highly burdened by malaria and anaemia that impair cognitive development. For the prospects of improving health in African citizens, understanding malaria and its relation to anaemia in school-aged children, it is cru...
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Global efforts to control Aedes mosquito-transmitted pathogens still rely heavily on insecticides. However, available information on vector resistance is mainly restricted to mosquito populations located in residential and public areas, whereas commercial settings, such as hotels are overlooked. This may obscure the real magnitude of the insecticid...
Article
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Background: Over the past decade, three strategies have reduced severe malaria cases and deaths in endemic regions of Africa, Asia and the Americas, specifically: (1) artemisinin-based combination therapy (ACT); (2) insecticide-treated bed nets (ITNs); and, (3) intermittent preventive treatment with sulfadoxine-pyrimethamine in pregnancy (IPTp). T...
Article
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Background Many studies have reported high efficacy and safety of artesunate-amodiaquine (AS-AQ) and artemether-lumefantrine (AL) when administered under direct observation in Cameroon. There is paucity of data to support their continuous use in home-based treatment of uncomplicated Plasmodium falciparum malaria in Cameroon. Hence, this study aimed...
Article
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Introduction: Identification of low birthweight and small for gestational age is pivotal in clinical management and many research studies, but in low-income countries, birthweight is often unavailable within 24 h of birth. Newborn weights measured within days after birth and knowledge of the growth patterns in the first week of life can help estim...
Article
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Background High altitude settings in Eastern Africa have been reported to experience increased malaria burden due to vector habitat expansion. This study explored possible associations between malaria test positivity rates and its predictors including malaria control measures and meteorological factors at a high-altitude, low malaria transmission s...
Article
Highly sensitive molecular techniques for the detection of low-level Plasmodium falciparum parasitemia are highly useful for various clinical and epidemiological studies. However, differences in how blood samples are preserved, the quantity of blood stored, as well as genomic DNA extraction methods used may compromise the potential usefulness of th...
Article
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Understanding the dynamics of larval habitat utilization by mosquito communities is crucial for the design of efficient environmental control strategies. The authors investigated the structure of mosquito communities found at hotel compounds in Zanzibar, networks of mosquito interactions with larval habitats and robustness of mosquito communities t...
Article
Background Rapid diagnostic tests (RDTs) have been extensively evaluated and play an important role in malaria diagnosis. However, the accuracy of RDT for malaria diagnosis in patients with sickle cell disease (SCD) is unknown. Methods We compared the performance of a histidine rich protein 2 (HRP-2) – based RDT (First Response®), and a lactate de...
Article
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Background: Asymptomatic malaria infections largely remain undetected and act as a reservoir for continuous transmission. The study assessed the prevalence of submicroscopic asymptomatic malaria infections and anaemia in two rural low (300 m above sea level) and highland (700 m asl) settings of Korogwe District north-eastern Tanzania. Methods: A...
Article
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Background A field survey was performed to investigate local environmental factors promoting occurrence and abundance of Aedes aegypti and Ae. bromeliae mosquitoes at hotel compounds in the south-east coastal region of Zanzibar Island. Methods The potential risk factors were determined using generalized linear mixed models. Aedes (Stegomyia) spp....
Article
The emergence of artemisinin-resistant Plasmodium falciparum parasites in Southeast Asia threatens malaria control and elimination. The interconnectedness of parasite populations may be essential to monitor the spread of resistance. Combining a published barcoding system of geographically restricted single-nucleotide polymorphisms (SNPs), mainly mi...
Article
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Mutations in the Plasmodium falciparum genes Pfdhfr and Pfdhps, particularly the sextuple mutant haplotype threatens the antimalarial effectiveness of sulfadoxine-pyrimethamine as intermittent preventive treatment during pregnancy (IPTp). To explore the impact of sextuple mutant haplotype infections on outcome measures after provision of IPTp-SP, w...
Article
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Background: Malaria remains highly endemic in Cameroon. The rapid emergence and spread of drug resistance was responsible for the change from monotherapies to artemisinin-based combinations. This systematic review and meta-analysis aimed to determine the prevalence and distribution of Plasmodium falciparum drug resistance markers within an evolvin...
Article
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Background: Individuals with sickle cell disease (SCD) are susceptible to infective conditions that predispose them to hemolysis and anemia. Folic acid is recommended as a preventative measure against anemia in SCD patients; however, there is scarce literature on the implications of this practice. Patients and methods: Plasma concentrations of f...
Article
Background: Acute malaria is associated with reticulocyte count depression, and artemisinin derivatives have also been shown to cause reversible count changes in patients with severe malaria. However, there has been no report on the effect of artemisinin on reticulocyte count when used in combination with other antimalarials, or the effect of artem...
Article
Background: Acute malaria is associated with reticulocyte count depression, and artemisinin derivatives have also been shown to cause reversible count changesin patients with severe malaria. However, there has been no report on the effect of artemisinin on reticulocytecountwhen used in combination with other antimalarials, or the effect of artemisi...
Preprint
Full-text available
Background Cameroon remains a country faced with high malaria burden despite enormous efforts made in the control of the disease. The rapid development and dispersal of mutations associated with anti-malarial drug resistance influenced policy changes from the use of chloroquine, amodiaquine and sulphadoxine-pyrimethamine to the adoption of artemisi...
Preprint
Full-text available
Background: Cameroon remains a country faced with high malaria burden despite enormous efforts made in the control of the disease. The rapid development and dispersal of mutations associated with anti-malarial drug resistance influenced policy changes from the use of chloroquine, amodiaquine and sulphadoxine-pyrimethamine to the adoption of artemis...
Preprint
Full-text available
Background: Cameroon remains a country faced with high malaria burden despite enormous efforts made in the control of the disease. The rapid development and dispersal of mutations associated with anti-malarial drug resistance influenced policy changes from the use of chloroquine, amodiaquine and sulphadoxine-pyrimethamine to the adoption of artemis...
Preprint
Full-text available
Background: Cameroon remains a country faced with high malaria burden despite enormous efforts made in the control of the disease. The rapid development and dispersal of mutations associated with anti-malarial drug resistance influenced policy changes from the use of chloroquine, amodiaquine and sulphadoxine-pyrimethamine to the adoption of artemis...
Preprint
Full-text available
Background There are several unknown illnesses including chikungunya and dengue viruses that present with fever in children. Therefore there are many cases that are misdiagnosed. Consequently we performed a study to determine the clinical characteristics of dengue and chikungunya in order to assist clinicians in management. Methods A total of 196...
Article
Aedes mosquitoes are the principal dengue vector in Taiwan, where the use of insecticides is a key element in the national control strategy. However, control efforts are constrained by the development of resistance to most insecticides, including pyrethroids. In this study, mutations in the voltage-gated sodium channel (VGSC) gene resulting in knoc...
Article
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Parasite resistance against anti-malarial drugs is a major threat to the ongoing malaria control and elimination strategies. This is especially true since resistance to the currently recommended artemisinins and partner drugs has been confirmed in South East Asia (SEA) and new anti-malarial compounds are not expected to be available in the near fut...
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Targeted Next Generation Sequencing (TNGS) is an efficient and economical Next Generation Sequencing (NGS) platform and the preferred choice when specific genomic regions are of interest. So far, only institutions located in middle and high-income countries have developed and implemented the technology, however, the efficiency and cost savings, as...
Article
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Excessive use of antibiotics, especially watch group antibiotics such as ceftriaxone leads to emergence and spread of antimicrobial resistance (AMR). In low and middle-income countries (LMICs), antibiotics are overused but data on consumption is scarcely available. We aimed at determining the extent and predictors of ceftriaxone use in a tertiary c...
Article
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Background: Large-scale surveillance of molecular markers of anti-malarial drug resistance is an attractive method of resistance monitoring, to complement therapeutic efficacy studies in settings where the latter are logistically challenging. Methods: Between 2014 and 2017, this study sampled malaria rapid diagnostic tests (RDTs), used in routin...
Article
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Background Reliable phenotypic antimicrobial susceptibility testing can be a challenge in clinical settings in low- and middle-income countries. WGS is a promising approach to enhance current capabilities. Aim To study diversity and resistance determinants and to predict and compare resistance patterns from WGS data of Acinetobacter baumannii with...
Article
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Background There is limited information on the safety or efficacy of currently recommended antimalarial drugs in patients with sickle cell disease (SCD), a population predisposed to worse outcomes if affected by acute malaria. Artesunate-amodiaquine (ASAQ) is the first-line treatment for uncomplicated malaria (UM) in many malaria-endemic countries...
Preprint
Full-text available
Real-time and large-scale surveillance of molecular markers of antimalarial drug resistance is a potential method of resistance monitoring, to complement therapeutic efficacy studies in settings where the latter are logistically challenging. This study investigates whether routinely used malaria rapid diagnostic tests (RDTs) can be used for massive...
Article
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This study aimed to use whole-genome sequencing to determine virulence and antimicrobial resistance genes in K. pneumoniae isolated from patients in a tertiary care hospital in Kilimanjaro. K. pneumoniae isolates from patients attending Kilimanjaro Christian Medical Centre between August 2013 and August 2015 were fully genome-sequenced and analysed...
Article
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Artemether–lumefantrine (AL) and artesunate–amodiaquine (AS-AQ) are the most commonly used artemisinin-based combination therapies (ACT) for treatment of Plasmodium falciparum in Africa. Both treatments remain efficacious, but single nucleotide polymorphisms (SNPs) in the P lasmodium falciparum multidrug resistance 1 ( Pfmdr1 ) gene may compromise...
Article
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Aedes aegypti is the main vector for dengue, chikungunya, yellow fever, Zika, and other arboviruses of public health importance. The presence of Ae. aegypti has never been systematically assessed in Zanzibar, including its preferred larval habitats. In 2016 we conducted a cross-sectional entomological survey to describe the preferred larval habitat...
Article
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Background Although the recent decline of malaria burden in some African countries has been attributed to a scale-up of interventions, such as bed nets (insecticide-treated bed nets, ITNs/long-lasting insecticidal nets, LLINs), the contribution of other factors to these changes has not been rigorously assessed. This study assessed the trends of Pla...
Article
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Background Limited information regarding the clonality of circulating E. coli strains in tertiary care hospitals in low and middle-income countries is available. The purpose of this study was to determine the serotypes, antimicrobial resistance and virulence genes. Further, we carried out a phylogenetic tree reconstruction to determine relatedness...
Article
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Emergence and spread of extended spectrum beta-lactamase (ESBL)-producing gram-negative bacteria, mainly due to CTX-M, is a major global public health problem. Patients infected with ESBL-producing gram-negative bacteria have an increased risk of treatment failure and death. We investigated the prevalence and risk factors for CTX-M gram-negative ba...
Article
Data on prevalence of antimalarial molecular resistance markers in pregnant women in Ghana is scarce. Prevalence of single nucleotide polymorphisms/haplotypes in thePfcrt,Pfmdr1,Pfdhfr, andPfdhpsgenes was assessed in a cross-sectional study involving 200 pregnant women. Almost 90% of infections were wild type at thePfcrtgene whereas thePfmdr1NFD mu...
Data
Haplotype description of 118 Plasmodium vivax isolates and epidemiologic information on residents and migrants with parasitemia, Greece, 2009–2013.
Data
Phylogenetic analyses of Plasmodium vivax isolates, Greece, 2009–2013.
Article
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Background: Plasmodium falciparum malaria remains a major health burden and genomic research represents one of the necessary approaches for continued progress towards malaria control and elimination. Sample acquisition for this purpose is troublesome, with the majority of malaria-infected individuals living in rural areas, away from main infrastru...
Article
Full-text available
Background The emergence of resistance against artemisinin combination treatment is a major concern for malaria control. ACTs are recommended as the rescue treatment, however, there is limited evidence as to whether treatment and re-treatment with ACTs select for drug-resistant P. falciparum parasites. Thus, the purpose of the present study is to i...
Data
Cumulative risk of crude treatment failure (PCR-unadjusted) by Pfmdr1 in patients treated with AL and ASAQ in the randomisation phase. Figure A1-A3 represent the risk of crude treatment failure in patents who received AL by Pfmdr1 variants. Figure B1-B3 represents the risk of crude treatment failure in participants who received ASAQ by Pfmdr1 varia...
Data
Multivariate logistic regression model of the association between Pfmdr1 SNPs and PCR-corrected recrudescence and new infections of patients treated with AL and ASAQ on day 28 follow-up in RCT phase. (DOCX)
Article
Full-text available
Objective To determine molecular epidemiology of methicillin-resistant S. aureus in Tanzania using whole genome sequencing. Methods DNA from 33 Staphylococcus species was recovered from subcultured archived Staphylococcus isolates. Whole genome sequencing was performed on Illumina Miseq using paired-end 2 × 250 bp protocol. Raw sequence data were...
Article
Full-text available
In Senegal, antimalarial drugs used in treatment and prevention of malaria are one of the main reasons for the current success in controlling malaria. However, the successful control of malaria is highly dependent on continued effectiveness of these drugs which may be compromised by the spread of drug resistance. Therefore, surveillance of drug res...
Article
Full-text available
Background Management of uncomplicated Plasmodium falciparum malaria relies on artemisinin-based combination therapies (ACTs). These highly effective regimens have contributed to reductions in malaria morbidity and mortality. However, artemisinin resistance in Asia and changing parasite susceptibility to ACT in Africa have now been well documented....
Article
Objective: To determine whether dihydroartemisinin-piperaquine (DHA-PPQ) is non-inferior to artesunate-amodiaquine (ASAQ) for treating uncomplicated malaria infection in pregnancy. Methods: 417 second/ third trimester pregnant women with confirmed asymptomatic Plasmodium falciparum parasitaemia were randomized to receive DHA-PPQ or ASAQ over 3 d...
Article
Full-text available
Genetic polymorphisms in P. falciparum can be used to indicate the parasite’s susceptibility to antimalarial drugs as well as its geographical origin. Both of these factors are key to monitoring development and spread of antimalarial drug resistance. In this study, we combine multiplex PCR, custom designed dual indexing and Miseq sequencing for hig...
Article
Artemisinin-based combination therapy (ACT) has been adopted as a strategy to mitigate multidrug resistance to antimalarial monotherapies. ACT combines the rapid and effective but rather short plasma half-life antimalarial action of an artemisinin derivative with a longer acting partner drug. Although the exact mechanisms of action of artemisinins...
Article
Full-text available
Background Dengue and chikungunya are mosquito-borne viral diseases of major global health concern. In Tanzania, information on risk factors for dengue and chikungunya is limited. We investigated individual, household, socio-economic, demographic and environmental risk factors for dengue and chikungunya seropositivity. Methods A cross sectional st...
Article
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Objective: To investigate knowledge and prevention practices regarding dengue and chikungunya amongst community members, as well as knowledge, treatment and diagnostic practices among healthcare workers. Method: We conducted a cross-sectional survey with 125 community members and 125 healthcare workers from 13 health facilities in six villages i...
Article
Sulphadoxine/pyrimethamine (SP) is still used for malaria control in sub-Saharan Africa; however, widespread resistance is a major concern. This study aimed to determine the dispersal and origin of sulphadoxine resistance lineages in the Democratic Republic of the Congo compared with East African Plasmodium falciparum dihydropteroate synthetase (Pf...
Article
Full-text available
Background Establishing in vitro Plasmodium falciparum culture lines from patient parasite isolates can offer deeper understanding of geographic variations of drug sensitivity and mechanisms of malaria pathogenesis and immunity. Cellulose column filtration of blood is an inexpensive, rapid and effective method for the removal of host factors, such...
Article
Full-text available
Background The emergence of resistance against artemisinin combination treatment (ACTs) is a major concern for malaria control. ACTs are recommended as rescue treatment; however, there is limited evidence on the impact of treatment and re-treatment with ACTs on selection for drug-resistant parasites. We aimed to investigate the impact of treatment...
Article
Full-text available
Background: Dengue and chikungunya are mosquito-borne viral diseases that are of public health importance throughout the tropical and subtropical regions of the world. Seasonal variations in transmission of these viruses have been suggested owing to the ecology of their mosquito vectors. However, little is known about the epidemiology of the diseas...